CHICAGO -- The Cubs added seven players for the final month of the regular season, including right-handed pitchers Brian Schlitter, Dan Straily and Arodys Vizcaino (ranked ninth among the club's prospects by MLB.com). The team also recalled left-handed pitcher Zac Rosscup and outfielder Junior Lake.

The Cubs selected the contracts of pitcher Eric Jokisch and catcher Rafael Lopez from Triple-A Iowa. Outfielder Justin Ruggiano was transferred to the 60-day disabled list to open a spot on the 40-man roster.

Vizcaino, acquired from the Braves in July 2012 for Paul Maholm and Reed Johnson, compiled a 3.51 ERA in 40 games at Class A Daytona, Double-A Tennessee and Iowa, giving up 16 earned runs on 38 hits and 18 walks over 41 innings. He pitched in the Major Leagues in 2011 with the Braves, and then he needed Tommy John surgery.

"He's got plus stuff -- his fastball, his breaking ball," Cubs president of baseball operations Theo Epstein said Tuesday. "The key for him this year was that he went out and established his health. He had his ups and downs. There were times when he was fighting his mechanics, and it wasn't his elite stuff. He fought through that."

Epstein said what they want Vizcaino to "learn what it's like to pitch at Wrigley Field with an eye on 2015."

Lake began the season with the Cubs, but he batted .216 in 98 games and was optioned to Iowa in mid-August. In 14 games with the Minor League team, he batted .262 with two home runs, three doubles and seven RBIs.

Jokisch was 9-10 with a 3.58 ERA in 26 starts at Iowa, striking out 143 over 158 1/3 innings. Lopez batted .285 at Iowa with one home run and 27 RBIs.

Both Jokisch and Lopez needed to be added this winter to the 40-man roster. Epstein said Lopez has made significant progress not only behind the plate, but as a hitter.

"He's someone our staff is excited to work with," Epstein said.

Jokisch, an 11th-round pick in the 2010 First-Year Player Draft, has compiled a 42-35 record and 3.50 ERA since his Minor League career began.

"He had an outstanding Minor League career," Epstein said. "What's helped him turn the corner is that he's become a true three-pitch pitcher. He has the slider that he can locate, and he can command his fastball to both sides of the plate. He really had a very consistent, very impressive season at Triple-A after an excellent year last year at Double-A. He's someone we see long term as a starting pitcher candidate. He still has some innings left."

The Cubs considered promoting Dallas Beeler, who made two spot starts June 28 against the Nationals and July 9 against the Reds, but Epstein said the right-hander had reached his innings limit this year. He was 9-6 with a 3.40 ERA in 124 1/3 innings at Iowa.

Another player who could join the Cubs is Mike Olt, who hit 12 home runs in 72 games before he was sent down to Iowa in late July. Olt was batting .139 at that point with 84 strikeouts in 187 at-bats. At Iowa, Olt batted .302 with seven home runs and nine doubles in 28 games before he was sidelined with a hamstring strain.

Schlitter and Rosscup both have been up with the Cubs this season. Straily was acquired from the Athletics in the Jeff Samardzija and Jason Hammel deal, and was 3-5 with a 4.09 ERA in 10 starts with Iowa.